scholarly journals Numerical Simulation of Plug Valve Design Parameters as Per Standards

2018 ◽  
Vol 8 (4) ◽  
pp. 455-466
Author(s):  
JVS. Praveen et al., JVS. Praveen et al., ◽  
Keyword(s):  
Numerical Simulation ◽  
Design Parameters ◽  
Valve Design ◽  
Plug Valve

Heat Exchange Calculation of a Regenerative Air Heater with Numerical Simulation Method

2013 ◽  
Vol 860-863 ◽  
pp. 1416-1419
Author(s):  
Ri Guang Wei ◽  
Zhen Xiao Qu ◽  
Jian Qiang Gao
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Calculation Model ◽  
Design Parameters ◽  
Practical Calculation ◽  
Air Preheater ◽  
Air Heater ◽  
Pulverized Coal Boiler ◽  
Set Up ◽  
Coal Boiler

According to the structure and working principle of rotary air preheater,the heat transfer calculation model is set up with reasonable simplification. Combining with the design parameters of the rotary air preheater of a 400 t/h pulverized coal boiler unit ,the results of practical calculation show that the said thermodynamic calculation method not only has higher precision of calculation,but also can get the temperature distributions of the gas, air and heat surface in each cross-section of the rotary air preheater. The result of numerical simulation calculation tallies well with the original designed data. It can be used for the heat calculation both two-sectorial and three-sectorial air heater; it can be used for performance analysis of the regenerative air heater.

Quasi-Periodicity, Chaos and Coexistence in the Time Delay Controlled Two-Cell DC–DC Buck Converter

2014 ◽  
Vol 24 (10) ◽  
pp. 1450124 ◽  
Author(s):  
Karama Koubaâ ◽  
Moez Feki
Keyword(s):  
Numerical Simulation ◽  
Time Delay ◽  
Chaotic Attractor ◽  
Chaotic Behavior ◽  
Buck Converter ◽  
Design Parameters ◽  
Bifurcation And Chaos ◽  
Different Types ◽  
2D Torus ◽  
Discrete Map

In addition to border collision bifurcation, the time delay controlled two-cell DC/DC buck converter is shown to exhibit a chaotic behavior as well. The time delay controller adds new design parameters to the system and therefore the variation of a parameter may lead to different types of bifurcation. In this work, we present a thorough analysis of different scenarios leading to bifurcation and chaos. We show that the time delay controlled two-cell DC/DC buck converter may also exhibit a Neimark–Sacker bifurcation which for some parameter set may lead to a 2D torus that may then break yielding a chaotic behavior. Besides, the saturation of the controller can also lead to the coexistence of a stable focus and a chaotic attractor. The results are presented using numerical simulation of a discrete map of the two-cell DC/DC buck converter obtained by expressing successive crossings of Poincaré section in terms of each other.

ON DESIGNING IMPEDANCE TUBE WITH GRAZING FLOW

Akustika ◽  
2021 ◽  
pp. 80
Author(s):  
Vadim Palchikovskiy ◽  
Igor Khramtsov ◽  
Aleksander Kuznetsov ◽  
Victor Pavlogradskiy
Keyword(s):  
Numerical Simulation ◽  
Analytical Solutions ◽  
Gas Dynamics ◽  
Aircraft Engine ◽  
Design Parameters ◽  
Experimental Setup ◽  
Structural Units ◽  
Impedance Tube ◽  
Acoustic Liners ◽  
Grazing Flow

The article considers the general issues arising in designing the experimental setup “Impedance tube with grazing flow”, the main structural units of the setup, and their purpose. It is given the basic requirements to be provided by the setup when testing samples of acoustic liners used in an aircraft engine. The choosing of the design parameters of the setup is based on the analysis of the known analytical solutions of the acoustics and gas dynamics, and on the numerical simulation of the grazing flow in the impedance tube.

Optimization Design of Agricultural Fans Based on Skewed-Swept Blade Technology

2019 ◽  
Vol 35 (2) ◽  
pp. 249-258
Author(s):  
Tao Ding ◽  
Lumeng Fang ◽  
Ji-Qin Ni ◽  
Zhengxiang Shi ◽  
Baoming Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Energy Efficiency ◽  
Optimization Design ◽  
Control Parameter ◽  
Rapid Development ◽  
Performance Testing ◽  
Design Parameters ◽  
Leakage Flow ◽  
Blade Design ◽  
Direction Control

Abstract.With the rapid development of modern agriculture facilities, agricultural fans have been widely used due to their low pressure and large airflow characteristics. However, existing agricultural fans have large flow losses and low energy efficiencies. To increase the airflow and energy efficiency of these fans, optimization designs based on skewed and swept blades were carried out. First, a “DDZ” agricultural fan (a leaf model agricultural fan commonly used in China) was chosen as the archetype fan. Its performance curves and flow field distribution were obtained by performance testing and numerical simulation. Second, the stack lines of the skewed blade and swept blade were designed based on the original blade, 3 skewed blade parameters (skewed angle a, x direction control parameter kx, and y direction control parameter ky), and 3 swept blade design parameters (swept angle ß, z direction control parameter kz, and r direction control parameter kr). Finally, the optimal skewed blade design parameters (a = 16.8°, kx = 1.65, and ky = 0.5) and optimal swept blade design parameters (ß = 10.6°, kz = -0.33, and kr =0.6) were obtained using numerical simulations and orthogonal testing, which is a response surface method. The numerical simulation results showed that the airflow and energy efficiency ratios of the optimal skewed blade fan were increased by 4.3% and 20.5%, and those of the optimal swept blade fan were increased by 4.5% and 15.4%, respectively, in comparison with those of the original fan. The flow fields showed that the optimal skewed blade mainly reduced the radial flow at the blade root and the leakage flow. The optimal swept blade mainly reduced the leakage flow by changing the distribution of the static pressure on the blade surfaces. Keywords: Agricultural fan, Skewed-Swept blade, Numerical simulation, Optimization.

Numerical Simulation and Experimental Study on Tar Decomposition of Low-Pressure Ejection Type Burner

2015 ◽  
Vol 1092-1093 ◽  
pp. 200-206
Author(s):  
De Fan Qing ◽  
Mao Kui Zhu ◽  
Yang Cheng Luo ◽  
Ya Long Zhang ◽  
Ai Rui Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Low Pressure ◽  
Orthogonal Test ◽  
Nozzle Diameter ◽  
Design Parameters ◽  
Minor Effect ◽  
Gas Flow Rate ◽  
Tar Cracking

The tar decomposition of low-pressure ejection type burner was researched. The burner used software to simulate and analyse impact of the nozzle diameter d, the gas flow rate V and the distance of the nozzle to the wall L on tar cracking. The orthogonal test were used for design parameters d, V and L, the optimization values of these three parameters were carried out, and experimental method was used for test the numerical simulation results. Numerical simulation and experimental results showed that the greatest impact on tar cracking is the nozzle diameter d, the minor effect is the distance of the nozzle to the wall L and the weakest effect is the gas flow rate V, and when the nozzle diameter d=4 mm, the distance L=18 mm and the gas flow rate V=0.10 m3/h, the tar cracking is the most efficiency.

scholarly journals Structure parameter optimization and bearing limit analysis of the expansion unit of three-roller tube expander

2020 ◽  
Vol 7 (5) ◽  
pp. 191630
Author(s):  
Gang Bi ◽  
Zhan Qu ◽  
Zhenquan Wang ◽  
Liangbin Dou ◽  
Mengmeng Li
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Gauge Length ◽  
Structure Design ◽  
Design Parameters ◽  
Roller Tube ◽  
Unit Structure ◽  
Drilling Technology ◽  
Expansion Force ◽  
Proper Length

The critical technical issues for the structure design of three-roller tube expander were first studied and analysed in this paper. Then, the major design parameters of the expansion unit structure and the bearing limit of 12¼″ three-roller tube expander were optimized and investigated by finite-element numerical simulation method. Results from study show that the required expansion force increases when the taper angle of the roller outer surface gets larger, taking the axial expansion force as the quantitative indicators. It is suggested that the roller tape angle of the expansion unit should be in the range of 9–12° considering the proper length of the roller and the non-self-locking tube expansion process. The required expansion force of the bellows first decreases and then increases when the gauge length of the expansion unit becomes longer. The optimal value of the gauge length is 50 mm considering the proper length of the roller. And according to the numerical simulation results, the designed three-roller tube expander meets the strength requirements. The results of this study are of great significance to the expend bellows drilling technology.

Parametric Analysis of Floor Cooling

2016 ◽  
Vol 861 ◽  
pp. 401-408
Author(s):  
Lucie Horká ◽  
Jan Weyr
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Numerical Simulation ◽  
Parametric Analysis ◽  
Cooling Water ◽  
Total Heat ◽  
Design Parameters ◽  
Total Heat Transfer ◽  
2D Numerical Simulation ◽  
Cooling Pipes

This study is aimed at parametric analysis of floor cooling. Impact of several design parameters such as air temperature, temperature of cooling water, distance of cooling pipes, thickness and thermal conductivity of top layer on total heat transfer of cooling floor is studied. The issue is solved by steady-state 2D numerical simulation of heat transfer to the floor construction. These parametric simulations are performed in software CalA. Impact of variable input parameters on total heat transfer is observed. Results of parametric analysis are displayed in a nomogram. This nomogram is useful for faster designing of floor cooling.

scholarly journals Numerical Simulation Study for the Performance of a Large Solar Hot Water System With Horizontal Storage Tank

2015 ◽  
Author(s):  
Ru Yang ◽  
Geng-Yi Lin
Keyword(s):  
Numerical Simulation ◽  
System Performance ◽  
Storage Tank ◽  
Large Scale ◽  
Cooling System ◽  
Water System ◽  
Thermal Storage ◽  
Hot Water ◽  
Design Parameters ◽  
Total Load

A large solar hot water system can be utilized to provide driving energy for heating system, heat-driven cooling system, as well as to provide hot water. This research addresses the effects of the storage tank design parameters on the performance of a large-scale solar hot water system with a horizontal storage tank. Most literatures only considered the stratification performance of the thermal storage tank itself instead of considering the overall system performance. Also, there is lack of experimental research data available for the design purpose. Therefore, this study employs a numerical simulation technique to study the design parameters effect of a horizontal thermal storage tank on the performance of a large-scale solar hot water system. In this study, the ANSYS-CFX program is employed to calculate the flow and temperature distributions inside horizontal thermal storage tank. Then the inlets and outlets of the tank are combined with the TRNSYS program to simulate the entire system performance under the weather of three representative cities of Taiwan, (Taipei, Taichung and, Kaohsiung). The results of the present study indicate that the vertical stratification baffles in the tank have important effects on system performance improvement. Quantitative increase of solar fraction of the total load is obtained. The comparison with the system with vertical storage tank is provided. The results of the present study can provide important reference for the large solar hot water system design in improving system efficiency.

Analysis on the Cycle Characteristics of Dual Swash Plate Stirling Engine

2013 ◽  
Vol 724-725 ◽  
pp. 946-950 ◽  
Author(s):  
Xu Dong Han ◽  
Wei Zheng Xu
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
Mechanical Energy ◽  
Stirling Engine ◽  
Design Parameters ◽  
Swash Plate ◽  
Fundamental Information ◽  
Waste Energy

Dual swash plate Stirling engine was designed to convert the waste energy of the flame to mechanical energy. A Stirling model has been developed and used to optimize the performance and design parameters of the engine. The Schmidt analysis is used to obtain the internal engine pressure for the adiabatic analysis. The objective of this paper is to provide fundamental information and present a detailed feasibility of dual the swash plate mechanism. Based on the theoretical model and numerical simulation, the Stirling power is calculated. The result shows that the swash plate mechanism could be applied in practice.

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